Soong: Read Android.soong.mk if skipping Android.mk

If Soong is enabled, and we're skipping an Android.mk because there is
an Android.bp file, check for an Android.soong.mk file and read that
instead. This will allow us to temporarily define modules or recurse
into subdirectories that soong does not yet support.

Change-Id: Ifdb2f0204a38a5069e53527f66ffcfb8008c11a4
diff --git a/core/definitions.mk b/core/definitions.mk
index d5840b8..57aa7b6 100644
--- a/core/definitions.mk
+++ b/core/definitions.mk
@@ -144,7 +144,10 @@
 define filter-soong-makefiles
 $(foreach mk,$(1),\
   $(if $(wildcard $(patsubst %/Android.mk,%/Android.bp,$(mk))),\
-    $(info skipping $(mk) ...),\
+    $(if $(wildcard $(patsubst %/Android.mk,%/Android.soong.mk,$(mk))),\
+      $(info skipping $(mk), but including Android.soong.mk ...)\
+        $(patsubst %/Android.mk,%/Android.soong.mk,$(mk)),\
+      $(info skipping $(mk) ...)),\
     $(mk)))
 endef
 else